Aircraft, including commercial aircraft and military aircraft, play a vital role in modern society. Commercial aircraft quickly and efficiently transport people and goods, thereby facilitating commerce. Military aircraft serve various roles, including personnel transportation and ordinance delivery, thereby ensure a strong and effective national defense. However, the noise generated by aircraft engines can be off-putting to some and has prompted complaints.
The noise generated by aircraft engines varies from aircraft-to-aircraft. Typically, the noise intensity level is a function of the velocity of the jet plume emitted by the aircraft engine. For example, supersonic aircraft produce a much more intense noise than subsonic aircraft. Therefore, supersonic aircraft tend to be more off-putting, and prompt more complaints, than typical commercial aircraft.
Furthermore, the activity of the aircraft may also be an aircraft noise consideration. For example, Field Carrier Landing Practices (FCLPs) performed by the United States Navy involve a series of touch-and-goes using a relatively short runway, thereby simulating landing and take-off from the deck of an aircraft carrier. The flight patterns and airspeeds required during Field Carrier Landing Practice tend to produce intense noise that emanates over long distances. Therefore, Field Carrier Landing Practices were traditionally performed at outlying airfields (OLFs). However, over time, outlying airfields become less outlying, thereby bringing the general public into closer proximity with Field Carrier Landing Practices.
Accordingly, those skilled in the art continue with research and development efforts in the field of jet noise suppression.